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TIS with Trig / GRT

L

lr172

Well Known Member
I just installed my new GRT setup with a Trig T22. I will be using GRT's new approved GPS antenna as my source input, but it won't be ready for a couple more weeks. I had hoped to get TIS traffic in the interim, as the Trig is 1090ES.

GRTs manual says that the TIS data comes over the main RS-232 interface and I have that connected and properly sending'/ receiving data. I did not connect the dedicated TIS output from the Trig.

I did a test flight today, but did not get a single traffic indication, though I was getting many via ADS-B on my ipad. I was flying in Ohare approach airspace and I can't imagine it doesn't have Mode S traffic broadcast.

I am wondering if it is a setup/config issue. I programmed in all the ADS-B parameters, except for the GPS input. I am wondering if the this could cause an issue.

Has anyone successfully received Mode S data with this setup? Any suggestions? GRT is shut down for the holidays, so no help from them.

Larry
 
ADS-B in

I have a TRIG 22 unit and it does not receive any ADS-B signal that I know of. It is a 1090ES transmitter only, unless they have changed it.
My GRT channels it thru a serial connection.
I have a Pathfinder receiver serial coupled to my GRT display to bring in weather and targets to that screen. The Pathfinder then wireless remotes it's data also to my iPad.
I'm not sure how you get targets on your iPad without a true receiver.
At least, that's how I understand it.
The GRT online forum is helpful and has been very quick for help with my problems.

John Koonce
N78MU
 
It sounds like he has ADSB-in only connected to an iPad. IMHO this is a mistake. Traffic is viewed much better on the GRT screen in front of you. (Unless your iPad is mounted in front of you). TIS coverage is spotty at best and won't get better. I honestly don't know if I get it or not, as I do have a Skyradar ADSB-in hooked up and it brings in everything.
 
Masterplumber said:
I have a TRIG 22 unit and it does not receive any ADS-B signal that I know of. It is a 1090ES transmitter only, unless they have changed it.


John Koonce
N78MU
Click to expand...

All transponders are both receivers (they listen for the 'ping') and transmitters. Mode S units can be addressed, and receive TIS traffic data if the FAA is sending it. But most ATC radar is not set up to do this. At least that's my experience.
 
Have you had the TT22 tested and signed off by someone with the right equipment and rating? That is supposed to be done before flying.
Did you ask ATC if they could see your mode S?
As I recall when you tell the GRT that you have ADSB a large spreadsheet appears in the setup menu. You need to fill in the info. I think that sheet may be needed for TIS, but I'm not really sure.

BTW, as I mentioned before, I recently put in a TT22, hooked to a 420W. Passed the FAA flight test and got my $500. However, I think the not yet released GRT source is not TSO'd so it won't qualify for the rebate. Given the stink with NavWorx and the FAA it will be interesting to see how this plays out.
One more thing: the TT22 uses a TNC connector, not the more common BNC. Be sure it is assembled correctly.
 
The adsb traffic will eventually flow to the GRT as well as the ipad. I just dont have the usb conterter that i needd for the stratux. Should have it in a week. I did ask a tower if they saw my transponder signal and they confirmed. I forgot to ask if they got a mode s signal. I have a ifr and transponder check set up for next week. The setup is complete for adsb and all other details including the mode s address. I just assumed chicago would be equipped but maybe not.
 
BobTurner said:
Have you had the TT22 tested and signed off by someone with the right equipment and rating? That is supposed to be done before flying.
Did you ask ATC if they could see your mode S?
As I recall when you tell the GRT that you have ADSB a large spreadsheet appears in the setup menu. You need to fill in the info. I think that sheet may be needed for TIS, but I'm not really sure.

BTW, as I mentioned before, I recently put in a TT22, hooked to a 420W. Passed the FAA flight test and got my $500. However, I think the not yet released GRT source is not TSO'd so it won't qualify for the rebate. Given the stink with NavWorx and the FAA it will be interesting to see how this plays out.
One more thing: the TT22 uses a TNC connector, not the more common BNC. Be sure it is assembled correctly.
Click to expand...

i did use a TNC connecter.
 
BTW, TIS-A is set up similar to ADSB ground stations. They only send traffic info if it's close to you. Maybe you didn't come close enough, e.g., 3500' vertically, or whatever the TIS distance requirements are.
 
GRT has a PDF that describes how to wire the Stratux to a GRT. The PDF also describes how to setup and program the GRT to receive ADS-B.
 
BobTurner said:
BTW, TIS-A is set up similar to ADSB ground stations. They only send traffic info if it's close to you. Maybe you didn't come close enough, e.g., 3500' vertically, or whatever the TIS distance requirements are.
Click to expand...

I had traffic that was 1 mile and 600 feet, as reported by ADSB and visual confirmation. Either I have a setup issue, or as you suggested, Chicago approach isn't set up to send Mode S traffic.

Thanks for your input on this.

Larry
 
I don't fly in O'Hare airspace, but I cannot imagine that don't have TIS-A capable radars in that RSA.

I would check to see if the protocols match between what the transponder is outputting and what the GRT expects. The serial connection that carries TIS data from the Trig is one-way, so TIS output pin 7 needs to get connected to an appropriate serial port input on the GRT. Similarly, there is a one-way serial connection for the GPS output to connect to the Trig on input pin 5. I don't see a bi-directional serial line(s) in their documentation for TIS or ADS-B functionality.

UPDATE: Forget what I wrote above about the pin assignments. GRT uses an adapter between the TrigTT22 and its EFIS(s). GRT says in their documentation Note 3 that Pin 7 is redundant in their installation (when using the adapter.)

I'll dig out a GRT manual when I get back later tonight, but the Trig manual is excerpted below.
Here it is: http://www.grtavionics.com/documents/supplements/TrigTransponderA2.pdf

Sections 3.1 and 3.2 are relevant.

It looks like the adapter is powered, so make sure it has power (probably does based on what you've said.)
I'll assume that you have followed all the instructions in section 3.1.
Step 3.1.5 gives you a menu of config options, I'd check if the GPS/TIS rate is correct for whatever GPS you currently have installed. Also check the TIS Output setting = Trig TIS Traffic.





TrigTT21/22 Manual for reference.

5.6.10 TIS Traffic Output

The TIS traffic is an RS232 output and supports the display of uplinked Traffic Information Service messages. The TT21/TT22 TIS output can drive the Trig proprietary traffic protocol, and can also support the format used by certain Garmin handheld displays, including the 495, 496, 695 and 696.

6.1.7 TIS Output

If the aircraft has a Traffic Information Service (TIS) compatible display connected to the transponder, select the appropriate interface protocol using the rotary knob.

6.1.9 GPS/TIS Line Speed
If a GPS input or TIS output has been configured, you should select the appropriate line speed using the rotary knob. Traffic displays using the
Garmin protocol run at 9600 bps. Panel mount GPS units with Aviation format outputs generally also run at 9600 bps. NMEA GPS units generally run at 4800 bps. Trig TN70, Freeflight 1201 and NexNav 3101 GPS receivers run at 19200 bps.
 
Last edited:
This is a very nice thread on GRT/TRIG 22. There is a Stratux in the system.
I might add one little wrinkle here. I have mine all hooked and going well, but my check showed I was not "legal".
At Oshkosh i talked with a TRIG rep. Mine is set up that my 430W (current software) sends GPS data to my GRT which serial relays that to the TRIG. Somehow the validity quality signature is degraded and the TRIG is now not considered to have a valid GPS signal, thus not a legal position source. The tech tells me that if I direct wire my 430W GPS signal to the GPS input on the TRIG adapter, that will override the GRT GPS source and I will be "legal".
Make sense?
Not looking forward to getting behind the panel again on my RV10 but plan to as soon as it warms up in the hangar. (Spring).

I also understood the standard Transponder freq system is not symmetrical, in that it receives the triggering "ping" on 1030 MHz and then transmits on 1090. So does the "ES" receive and transmit on 1090?

John Koonce
N78MU
 
My experience from a recent panel change. The 430W navigator needed an update to be compatible with an ES transponder which you have. Then a separate wire from the 430W had to be installed between it and the transponder.
The 430W update was not a big deal, done at the local avionics shop and adding the wire was not so bad. Somewhat of a PITB maybe but it worked out well. There is a second ser out on the 430W for the extra wire to plug into that goes to the transponder and the existing wire that goes to the EFIS from the 430W remains there for EFIS and mapping needs. The 430W will then need to have the settings for the ser output belonging to the new wire set to ADSB. Your AV shop can confirm all this as it was a year ago since I did this and I am old, so is my memory. :)) BTW this was for the AFS/Dynon Trig unit and I believe they are the same regarding using the 430W as the ADSB source.
 
maus92 said:
I don't fly in O'Hare airspace, but I cannot imagine that don't have TIS-A capable radars in that RSA.

I would check to see if the protocols match between what the transponder is outputting and what the GRT expects. The serial connection that carries TIS data from the Trig is one-way, so TIS output pin 7 needs to get connected to an appropriate serial port input on the GRT. Similarly, there is a one-way serial connection for the GPS output to connect to the Trig on input pin 5. I don't see a bi-directional serial line(s) in their documentation for TIS or ADS-B functionality.

UPDATE: Forget what I wrote above about the pin assignments. GRT uses an adapter between the TrigTT22 and its EFIS(s). GRT says in their documentation Note 3 that Pin 7 is redundant in their installation (when using the adapter.)

I'll dig out a GRT manual when I get back later tonight, but the Trig manual is excerpted below.
Here it is: http://www.grtavionics.com/documents/supplements/TrigTransponderA2.pdf

Sections 3.1 and 3.2 are relevant.

It looks like the adapter is powered, so make sure it has power (probably does based on what you've said.)
I'll assume that you have followed all the instructions in section 3.1.
Step 3.1.5 gives you a menu of config options, I'd check if the GPS/TIS rate is correct for whatever GPS you currently have installed. Also check the TIS Output setting = Trig TIS Traffic.





TrigTT21/22 Manual for reference.

5.6.10 TIS Traffic Output

The TIS traffic is an RS232 output and supports the display of uplinked Traffic Information Service messages. The TT21/TT22 TIS output can drive the Trig proprietary traffic protocol, and can also support the format used by certain Garmin handheld displays, including the 495, 496, 695 and 696.

6.1.7 TIS Output

If the aircraft has a Traffic Information Service (TIS) compatible display connected to the transponder, select the appropriate interface protocol using the rotary knob.

6.1.9 GPS/TIS Line Speed
If a GPS input or TIS output has been configured, you should select the appropriate line speed using the rotary knob. Traffic displays using the
Garmin protocol run at 9600 bps. Panel mount GPS units with Aviation format outputs generally also run at 9600 bps. NMEA GPS units generally run at 4800 bps. Trig TN70, Freeflight 1201 and NexNav 3101 GPS receivers run at 19200 bps.
Click to expand...

Thanks for the input. I did read and follow the install manual and Trig supplement, as well as the Trig manual. I have followed all of the details and configured all paraameters accordingly, except hte GPS input speed. I did set the GPS integrity and other parameters related to ADS-B, which made me think that maybe it somehow shuts off the Mode S.

The GRT folks are back on Tuesday and I imagine they will be able to fix me up.

Larry
 
Masterplumber said:
This is a very nice thread on GRT/TRIG 22. There is a Stratux in the system.
I might add one little wrinkle here. I have mine all hooked and going well, but my check showed I was not "legal".
At Oshkosh i talked with a TRIG rep. Mine is set up that my 430W (current software) sends GPS data to my GRT which serial relays that to the TRIG. Somehow the validity quality signature is degraded and the TRIG is now not considered to have a valid GPS signal, thus not a legal position source. The tech tells me that if I direct wire my 430W GPS signal to the GPS input on the TRIG adapter, that will override the GRT GPS source and I will be "legal".
Make sense?
Not looking forward to getting behind the panel again on my RV10 but plan to as soon as it warms up in the hangar. (Spring).

I also understood the standard Transponder freq system is not symmetrical, in that it receives the triggering "ping" on 1030 MHz and then transmits on 1090. So does the "ES" receive and transmit on 1090?

John Koonce
N78MU
Click to expand...

The ES means extended squitter - extra bits (ADSB-out data) transmitted on 1090. Mode S transponders can also receive extra data (TIS-A traffic, reply/don't reply signal) on 1030 MHz.
Your TT-22 needs a lot more info from your gps than just position to be 2020 compliant. All that data is contained in Garmin's ADSB+ format (which the EFIS does not use). So wire up a second RS232 port on the GPS, set it to ADSB+ (you must have the +, if you don't see it in the list then you need a software upgrade). Wire this RS232 line directly to the TT22 adaptor GPS in connection.
 
TRIG 22/GRT

Thanks for the info.
I already have the ADSB+, but it only goes to the EFIS. I split my panel into three sections and shoehorned a GRT 12" display into the pilot section. Changed out a 327 to the TRIG. Added a Pathfinder. That required more back panel work than I expected, but finally done and all works, except for this.
Now a bit more wiring and I am there. Free weather on a 12" display is great! No more Garmin XM weather payments for my 396.

Thanks again for the advice.

John Koonce
N78MU
 
Hi Larry,

I'm not sure your question was answered. The TT22 will output radar-derived TIS-A (not ADS-B traffic) if your local radar is the right type and still delivers this data. If so, pin 7 and a gnd from the TT-22 will have that data and this should go to an RS-232 input on the GRT. I've never run this to a GRT but have installed a few TT22s connected to Garmin GPS units and the traffic works fine on those.

You might check out this GRT doc. I believe the GTX-330 outputs the same format for TIS-A as the TT22: http://www.grtavionics.com/documents/supplements/GTX330SupplementA1.pdf
 
Talked to GRT today and thought I would share the detail. Apparently the Trig adapter takes the Pin 7 TIS Output and multiplexes it with the main RS-232 TX connection from the Trig. The documentation incorrectly shows this pin as a pass through in their adapter, though it probably does pass it through as well.

Second, the manual is incorrect in it's configuration detail. The GRT wants the Garmin format of the TIS stream, but the manual indicates to use the Trig format.

While I like the GRT product, they don't score very high in the Documentation department.

Wx was **** today, but will report results once I get a flight in.

Larry
 
lr172 said:
Talked to GRT today and thought I would share the detail. Apparently the Trig adapter takes the Pin 7 TIS Output and multiplexes it with the main RS-232 TX connection from the Trig. The documentation incorrectly shows this pin as a pass through in their adapter, though it probably does pass it through as well.

Second, the manual is incorrect in it's configuration detail. The GRT wants the Garmin format of the TIS stream, but the manual indicates to use the Trig format.

While I like the GRT product, they don't score very high in the Documentation department.

Wx was **** today, but will report results once I get a flight in.

Larry
Click to expand...

Thanks for the info. Follow up to open questions is really helpful.
 
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